JP4234045B2 - Steering damper device - Google Patents

Description

  The present invention relates to a steering damper device used for a small vehicle such as a motorcycle.

  In motorcycles, steering is performed by turning a front fork that supports the front wheels about a steering stem that is rotatably inserted into the head pipe at the front end of the vehicle body frame by a steering operation. Yes. Such a motorcycle may be equipped with a steering damper device between a steering side member that is turned by a steering wheel operation and a vehicle body side member that is not turned by a steering wheel operation. In that case, the steering damper device generates almost no damping moment in normal driving where the steering angle of the steering wheel is small and the angular velocity is low, and a high damping moment is generated in a region where the steering angle of the steering wheel is large and the angular velocity is high. There is a demand for making the damping moment hardly occur when returning the steered steering.

  The present inventors have previously proposed a steering damper device that can satisfy such a demand while using a cylindrical damper with a simple structure and low price (Japanese Patent Application No. 2003-301072). In the steering damper device, one of a damper case and a damper rod constituting a cylindrical damper is rotatably connected to a vehicle body side member such as a head pipe, and the other is rotated to a steering side member such as a fork bridge. The cylindrical damper is connected so as to be in the most contracted or extended state when the handle is in the neutral position, that is, when the steering angle of the handle is 0 °.

  According to such a steering damper device, the damper rod of the cylindrical damper slides in the same direction in the damper case even when the steering wheel is cut to the left or right side, so that it has a symmetrical damper characteristic. Can be made. When returning the handle, in any case, the damper rod slides in the opposite direction, so that almost no damping force can be generated. Moreover, the amount of sliding of the damper rod with respect to the steering wheel steering angle is small when the steering wheel steering angle is near 0 °, and increases as the steering wheel steering angle goes away from 0 °. Further, the damping force that acts on the steering side member from the cylindrical damper is small when the steering angle of the steering wheel is near 0 °, and increases as the steering angle of the steering wheel is separated from 0 °. Therefore, almost no damping force is generated during normal traveling with a small steering angle and a low angular velocity, and a high damping moment can be generated in a region where the steering angle is large and the angular velocity is high.

  By the way, in the case of the steering damper device in which the cylindrical damper is arranged as described above, mechanically, the damping moment increases as the steering angle of the steering wheel increases. Such a characteristic is basically preferable for the steering damper device, but when a large steering angle is required during low-speed traveling, a slight steering weight may be felt.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a steering damper device capable of relatively lightly operating a steering wheel even in a region where a steering wheel steering angle is large.

In order to achieve the above object, the present invention according to claim 1 is directed to a tubular member in which a damper rod slides within a damper case, a steering side member that rotates around a steering stem by a steering operation, and a steering operation. In the steering damper device provided between the vehicle body side member that does not rotate even if the steering angle of the damper rod with respect to the steering angle of the steering wheel is small near the steering angle of 0 °, the steering angle of the steering wheel is 0 °. When the steering angle of the tubular damper corresponding to the magnitude of the damping force with respect to the sliding amount of the damper rod is turned from 0 °, the steering angle of the steering wheel is increased. Is larger in the vicinity of 0 °, and the steering angle becomes smaller as the steering angle goes away from 0 °, and the steering angle becomes 0. When returned to °, the steering wheel is made smaller than when the steering angle is turned from 0 °.

According to a second aspect of the present invention, there is provided a tubular damper in which a damper rod slides in a damper case, a steering side member that rotates around a steering stem by a handle operation, and a vehicle body that does not rotate by a handle operation. In the steering damper device provided between the steering member and the side member, the damping force acting on the steering side member from the cylindrical damper is small when the steering angle is 0 °, and the steering angle is away from 0 °. And the damping coefficient of the cylindrical damper corresponding to the magnitude of the damping force with respect to the sliding amount of the damper rod is 0 when the steering angle of the steering wheel is cut from 0 °. It is large in the vicinity of °, and becomes smaller as the steering angle of the steering wheel goes away from 0 °. When the handle is characterized in that it is set smaller than when cut from the steering angle 0 °.

According to a third aspect of the present invention, there is provided a steering-side member in which a damper rod slides in a damper case, a steering-side member that rotates about a steering stem by a handle operation, and a vehicle body that does not rotate by a handle operation. In the steering damper device provided between the side member and the steering damper device, the sliding amount of the damper rod with respect to the steering angle of the steering wheel is small when the steering angle of the steering wheel is 0 °, and increases as the steering angle of the steering wheel is away from 0 °. The damping force that acts on the steering side member from the cylindrical damper is also small when the steering angle of the steering wheel is near 0 °, increases as the steering angle of the steering wheel goes away from 0 °, and the sliding amount of the damper rod damping coefficient of the cylindrical damper which corresponds to the magnitude of the damping force relative to the handle is Misao When the steering angle is turned from 0 °, the steering angle is large in the vicinity of 0 °, and becomes smaller as the steering angle of the steering wheel is away from 0 °. When the steering wheel is returned to the steering angle of 0 °, the steering angle is 0 °. It is characterized by being made smaller than when it is cut off.

  According to a fourth aspect of the present invention, in addition to the invention according to any one of the first to third aspects, the cylinder damper rod includes first and second damper chambers for accommodating oil in the damper case. A piston partitioning the chamber is attached, and a passage is provided between the first and second chambers for flowing oil between the first and second chambers as the piston slides. Is changed according to the sliding position of the piston, when the steering wheel is turned from 0 °, the steering angle is large in the vicinity of 0 °, and the steering angle is separated from 0 °. Accordingly, when the steering wheel is returned to the steering angle of 0 °, the steering wheel is made smaller than when the steering wheel is turned from the steering angle of 0 °.

  The passage corresponds to the first through hole 24, the second through hole 25, the flow path 51, and the groove 41 in the embodiment of the present invention described later, and the first chamber and the second chamber are It corresponds to the upper chamber 15a and the lower chamber 15b in the embodiment.

  In addition to the invention according to claim 4, the present invention according to claim 5 is characterized in that the piston has a first passage through which oil flows between the first and second chambers as the piston slides. A first valve plate is provided that opens the first passage when the steering wheel is turned from a steering angle of 0 °, and closes the first passage when the steering wheel is returned to the steering angle of 0 °. One valve plate is urged by the first valve spring in the closing direction of the first passage, and the urging force of the first valve spring is large in the vicinity of the steering angle of 0 °, and the steering angle of the steering wheel is 0 °. And the piston is provided with a second passage through which oil flows between the first and second chambers as the piston slides, and the steering wheel has a steering angle of 0 °. When cut When the second passage is closed and the steering wheel is returned to the steering angle of 0 °, a second valve plate for opening the second passage is attached, and the second valve plate is moved in the closing direction of the second passage by the second valve spring. The biasing force of the second valve spring is made smaller than the biasing force of the first valve spring against the first valve plate.

  Furthermore, in the present invention according to claim 6, in addition to the invention according to claim 4, the piston has a first passage through which oil flows between the first and second chambers as the piston slides. When the steering wheel is turned from a steering angle of 0 °, the first passage is opened, and when the steering wheel is returned to the steering angle of 0 °, the first passage is closed and biased in the closing direction. A first valve plate is attached, and the piston is provided with a second passage through which oil flows between the first and second chambers as the piston slides, and the steering wheel is turned from a steering angle of 0 °. The second passage is closed when the steering wheel is returned to a steering angle of 0 °, and the second passage is opened when the steering wheel is returned to the steering angle of 0 °. The biasing force in the closing direction is the first valve spring. It is made smaller than the urging force in the closing direction, and the damper case is provided with a groove that communicates between the first and second chambers only when the steering angle of the steering wheel is larger than a predetermined value. Features.

  In addition to the invention according to claim 4, the present invention according to claim 7 includes a first passage through which the oil flows between the first and second chambers as the piston slides. When the steering wheel is turned from a steering angle of 0 °, the first passage is opened, and when the steering wheel is returned to the steering angle of 0 °, the first passage is closed and biased in the closing direction. A first valve plate is attached, and the piston is provided with a second passage that allows oil to flow between the first and second chambers as the piston slides. When the steering wheel is turned, the second passage is closed, and when the steering wheel is returned to the steering angle of 0 °, the second passage is opened, and a second valve plate that is biased in the closing direction is attached. Urging force in the closing direction of the first valve Further, the piston is provided with a third passage through which oil flows between the first and second chambers as the piston slides, while the damper case is provided with the damper case. Is provided with a tapered protrusion inserted into the third passage, and the protrusion is formed in a tapered shape so as to increase the flow passage area of the first passage as the steering angle of the steering wheel moves away from 0 °. It is characterized by.

  The first passage, the second passage, and the third passage correspond to a first through hole 24, a second through hole 25, and a flow path 51, respectively, in an embodiment of the present invention that will be described later.

According to the first aspect of the present invention, the sliding amount of the damper rod with respect to the steering wheel steering angle is small when the steering wheel steering angle is near 0 °, and is increased as the steering wheel steering angle goes away from 0 °. Therefore, basically, a damping force hardly occurs in a region where the steering wheel steering angle is small, and the damping force increases as the steering wheel steering angle increases. Moreover, in the present invention, the damping coefficient of the cylindrical damper, that is, the magnitude of the damping force with respect to the sliding amount of the damper rod is large when the steering wheel is turned from 0 °. The steering wheel angle decreases as it moves away from 0 °, and when the steering wheel is returned to the steering angle of 0 °, it is made smaller than when the steering wheel is turned from the steering angle of 0 °. Sometimes the damping force is prevented from increasing excessively. Accordingly, the steering operation feels heavy during low-speed traveling where a large steering angle is required, while maintaining the characteristics required for a steering damper device such as a motorcycle in which the damping force increases as the steering angle increases. it can be prevented, also, when returning the cut big handle, the damping force is scarcely generated, nimble return is made possible of the handle.

According to the second aspect of the present invention, the damping force acting on the steering side member from the cylindrical damper is small when the steering angle of the steering wheel is 0 °, and increases as the steering angle of the steering wheel is separated from 0 °. In addition, since the damping coefficient of the cylindrical damper is reduced in the region where the steering angle of the steering rod is large where the amount of sliding of the damper rod is large, the steering wheel steering is performed in the same manner as in the first aspect of the invention. while such characteristics that also increases the damping force according to an increase of the angle is maintained, it can be prevented that a large steering angle so the steering wheel operation is felt heavier during low-speed travel is required, also larger When the cut handle is returned, almost no damping force is generated, and the handle can be returned easily.

  And according to this invention concerning the said Claim 3, since it has the characteristic of each invention concerning the said Claim 1 and 2 together, the effect similar to those invention can be acquired.

  According to the fourth aspect of the present invention, the flow resistance of the passage communicating between the first and second chambers in the damper case is large when the steering angle is 0 °, and the steering angle is 0 °. By decreasing the distance from the steering wheel, the damping coefficient of the cylindrical damper is decreased when the steering wheel is turned from 0 °, and the steering angle is increased in the vicinity of 0 °, and is decreased as the steering angle is increased from 0 °. When the steering wheel is returned to the steering angle of 0 °, the steering wheel can be made smaller than when the steering wheel is turned from the steering angle of 0 °.

  According to the fifth aspect of the present invention, the piston is provided with the first passage through which oil flows between the first and second chambers as the piston slides, and the steering wheel has a steering angle. A first valve plate is attached that opens the first passage when it is cut from 0 °, and closes the first passage when the steering wheel is returned to a steering angle of 0 °. The first valve plate is attached by a first valve spring. The first valve spring is biased in the closing direction of the first passage, and the biasing force of the first valve spring is increased in the vicinity of the steering wheel steering angle of 0 °, and is decreased as the steering wheel steering angle moves away from 0 °. The piston is provided with a second passage through which oil flows between the first and second chambers as the piston slides, and when the steering wheel is turned from 0 °, the second passage is provided. Close and handle When the steering angle is returned to 0 °, a second valve plate that opens the second passage is attached, and the second valve plate is urged in the closing direction of the second passage by a second valve spring. The urging force of the two-valve spring is made smaller than the urging force of the first valve spring against the first valve plate, whereby the effect of the invention of claim 4 can be achieved.

  According to the sixth aspect of the present invention, the piston is provided with the first passage through which oil flows between the first and second chambers as the piston slides, and the steering wheel has a steering angle. The first passage is opened when it is cut from 0 °, the first passage is closed when the steering wheel is returned to the steering angle of 0 °, and a first valve plate that is biased in the closing direction is attached, and The piston is provided with a second passage through which oil flows between the first and second chambers as the piston slides, and when the handle is turned from 0 °, the second passage is closed. When the steering wheel is returned to the steering angle of 0 °, a second valve plate that opens the second passage and is biased in the closing direction is attached, and the biasing force of the second valve plate in the closing direction is Less than the biasing force in the closing direction of the first valve spring The damper case is provided with a groove that communicates between the first and second chambers only when the steering angle of the steering wheel becomes larger than a predetermined value, thereby achieving the effect of the invention of claim 4. can do.

  According to the seventh aspect of the present invention, the piston is provided with the first passage through which oil flows between the first and second chambers as the piston slides, and the steering wheel has a steering angle. The first passage is opened when it is cut from 0 °, the first passage is closed when the steering wheel is returned to the steering angle of 0 °, and the first valve plate that is biased in the closing direction is attached. The piston is provided with a second passage for allowing oil to flow between the first and second chambers as the piston slides, and when the steering wheel is turned from 0 °, the second passage is opened. When the steering wheel is closed and the steering angle is returned to 0 °, a second valve plate that opens the second passage and is biased in the closing direction is attached, and the biasing force of the second valve plate in the closing direction is Smaller than the biasing force in the closing direction of the first valve spring Further, the piston is provided with a third passage through which oil flows between the first and second chambers as the piston slides, while the damper case is provided with the third passage. The tapered protrusion to be inserted is provided, and the protrusion is formed in a tapered shape so as to increase the flow area of the first passage as the steering angle of the steering wheel is separated from 0 °. The effects of the invention can be achieved.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below based on preferred examples of the present invention shown in the accompanying drawings.

  1 to 10 show a first embodiment of a steering damper device according to the present invention. FIG. 1 is a side view showing a main part of a motorcycle equipped with the steering damper device. FIG. FIG. 3 is a sectional view of a cylindrical damper portion taken along line 3-3 in FIG. 2, and FIG. 4 is an enlarged sectional view taken along line 4-4 in FIG. 5 is a sectional view taken along line 5-5 in FIG. 4, FIG. 6 is a sectional view taken along line 6-6 in FIG. 4, FIG. 7 is an exploded perspective view of the piston of the cylindrical damper, and FIG. FIG. 9 is a front view similar to FIG. 2 showing a state when turning from the position to the left side, FIG. 9 is a sectional view taken along line 9-9 of FIG. 8, and FIG. 10 is a characteristic curve diagram of the steering damper device.

  As shown in FIGS. 1 and 2, the front fork 2 that supports the front wheel 1 of the motorcycle includes left and right fork pipes 3 and 3 and a fork bridge 4 that connects the upper ends of the fork pipes 3 and 3. The fork bridge 4 is composed of a top bridge 4a and a bottom bridge 4b that are spaced apart in parallel in the vertical direction, and a steering stem 5 that connects the bridges 4a and 4b to each other in the horizontal direction is provided. It has been. The steering stem 5 is rotatably inserted into a head pipe 6 h provided at the front end of the vehicle body frame 6. A steering handle 7 is attached to the top bridge 4a. Thus, by operating the handle 7, the front fork 2 rotates left and right about the steering stem 5, and the front wheel 1 supported by the front fork rotates with it, thereby steering the motorcycle. It is like that.

  The head pipe 6h is provided with a stay 8 that protrudes forward at a position near its lower end. The stay 8 is disposed on a vehicle body center plane extending in the vehicle body longitudinal direction. The bottom bridge 4b is also provided with a stay 9 projecting forward at the center in the left-right direction. A cylindrical damper 10 is disposed between the stays 8 and 9. That is, the cylindrical damper 10 is disposed in front of the head pipe 6h so as to be substantially along the longitudinal direction of the head pipe 6h.

  As shown in FIG. 3, the cylindrical damper 10 includes a damper case 11 and a damper rod 12 that slides in the damper case 11, and the damper case 11 is connected to a head pipe 6 h via a spherical joint 13. The damper rod 12 is rotatably connected to the bottom bridge 4b side, that is, the steering side stay 9 via a spherical joint 14, via a spherical joint 14. The center axis of the damper rod 12 that slides inside the damper case 11, that is, the center axis D of the cylindrical damper 10 passes through the centers of the spherical joints 13 and 14. Thus, the cylindrical damper 10 is attached between the vehicle body frame 6 that does not rotate even when the handle 7 is operated and the front fork 2 that rotates as the handle 7 is operated. As shown in FIG. 2, the cylindrical damper 10 is in the most contracted state when the handle 7 is in the neutral position, that is, when the steering angle of the handle is 0 °, and the central axis D of the cylindrical damper 10 is The steering stem 5 is parallel to the central axis S of the steering stem 5. Therefore, at that time, the center axis D of the cylindrical damper 10 is positioned on the plane in the vehicle longitudinal direction including the center axis S of the steering stem 5, that is, on the vehicle center plane.

  As shown in FIG. 3, the damper case 11 of the cylindrical damper 10 includes a damper chamber 15 and a reservoir chamber 17 that communicates with the damper chamber 15 via an oil passage 16. Oil is enclosed in the damper chamber 15 and the reservoir chamber 17. The lower surface of the reservoir chamber 17 is formed by a piston 18, and the piston 18 is urged upward by a compressed gas 19 enclosed in a gas chamber below the reservoir chamber 17. The damper chamber 15 is divided into two upper and lower chambers 15 a and 15 b by a piston 20 attached to the tip of the damper rod 12.

  4 to 7, the piston 20 includes a piston body 23 having a plurality of notches 21, 21,..., 22, 22. The piston body 23 penetrates in the vertical direction, and the upper end opens to the upper end surface of the piston body 23 and the lower end opens to the notch 22. The lower end is the piston body 23. Are provided with second through holes 25, 25,. The upper end of the first through hole 24 is controlled to open and close by a valve plate 26 made of an elastic plate, and the lower end of the second through hole 25 is controlled to open and close by a similar valve plate 27. The upper valve plate 26 is fixed at its central portion via a washer 29 by a nut 28 fastened to the upper end portion of the damper rod 12, and its peripheral portion is between the upper end surface of the damper chamber 15. The valve spring 30 is urged downward by a washer member 31 and is normally held in close contact with the upper end surface of the piston body 23. The washer member 31 is also provided with a plurality of notches 31a, 31a,. Further, the lower valve plate 27 is pressed and biased upward by a valve spring 33 that is contracted between the lower spring plate 32 and a spring receiver 32 supported by the damper rod 12. 23 is held in close contact with the lower end surface of 23. The upper valve spring 30 is sufficiently larger in spring force than the lower valve spring 33.

  In the cylindrical damper 10 including the piston 20 having such a configuration, when the piston 20 attached to the tip of the damper rod 12 slides toward the lower side of the damper chamber 15 when extending, The pressure in the lower chamber 15b of the damper chamber 15 increases. Then, the pressure acts from the lower surface side to the outer peripheral portion of the valve plate 26 through the first through hole 24 from the notch portion 22 on the outer periphery of the lower end portion of the piston body 23, so that the outer peripheral portion of the valve plate 26 is The valve spring 30 is pushed up against the urging force of the valve spring 30 as shown by a two-dot chain line in FIG. As a result, the oil in the lower chamber 15b flows to the upper chamber 15a as shown by the solid line arrow in FIG. A damping force is generated by the resistance of the oil passing through the gap between the valve plate 26 and the piston main body 23. In this case, the load applied from the valve spring 30 to the valve plate 26 increases as the deflection amount of the valve spring 30, that is, the compression amount increases, so that when the cylindrical damper 10 is contracted, the valve plate 26 and the piston body 23 The gap is small, and the gap increases as the cylindrical damper 10 extends. Therefore, the damping coefficient of the cylindrical damper 10, that is, the magnitude of the damping force with respect to the sliding amount of the damper rod 12 is large when the cylindrical damper 10 is contracted, and decreases as it expands.

  On the other hand, when the cylindrical damper 10 contracts, the pressure in the upper chamber 15a of the damper chamber 15 increases, so that the peripheral portion of the lower valve plate 27 is lower as shown by the two-dot chain line in the lower right portion of FIG. It deforms downward against the urging force of the valve spring 33. As a result, the gap between the valve plate 27 and the lower end surface of the piston body 23 is opened, and the oil in the upper chamber 15a passes through the second through hole 25 as shown by the broken line arrow in FIG. It flows to 15b. In that case, since the pressing force applied to the peripheral portion of the valve plate 27 by the valve spring 33 is small, the valve plate 27 is easily deformed. Therefore, almost no damping force is generated at this time.

  Next, the operation of the steering damper device configured as described above will be described.

  As described above, when the handle 7 is in the neutral position, that is, when the steering angle is 0 °, the cylindrical damper 10 is in the shortest contracted state. In this state, when the handle 7 is turned to the left, for example, as shown in FIG. 8, the front fork 2 moves leftward about the steering stem 5 that is rotatably inserted into the head pipe 6h of the vehicle body frame 6. Rotate. Accordingly, the bottom bridge 4b that constitutes the fork bridge 4 of the front fork 2 also rotates in the same manner, and a spherical joint that connects the stay 9 provided at the center portion in the left-right direction and the damper rod 12 of the cylindrical damper 10. 14 deviates from the vehicle center plane in the vehicle longitudinal direction. On the other hand, the spherical joint 13 that connects the stay 8 provided in the head pipe 6h and the damper case 11 of the cylindrical damper 10 does not rotate the head pipe 6h even if the handle 7 is operated. That is, it is on the center plane of the vehicle body in the longitudinal direction of the vehicle body. As a result, the cylindrical damper 10 extends, and the damper rod 12 slides downward in the damper case 11 in FIG. 3, and a damping force is generated.

  Further, when the handle 7 is turned to the right, the cylindrical damper 10 similarly extends, and the damper rod 12 slides downward in the damper case 11 in FIG. Accordingly, a damping force is generated. Thus, in this cylindrical damper 10, the damper rod 12 slides in the same direction in the damper case 11 when the handle 7 is steered to the left or right side from the position where the steering angle of the steering wheel is 0 °. It is provided as such.

  Moreover, when the handle 7 is turned to the right or to the left, if the turning angle of the handle 7, that is, the steering angle is the same, the extension amount of the cylindrical damper 10 is the same. Therefore, the damping force characteristic is symmetrical as shown in FIG.

  When the handle 7 cut to the right or left is returned to the neutral position, the cylindrical damper 10 contracts in any case, and the damper rod 12 slides upward in the damper case 11 in FIG. . As described above, the cylindrical damper 10 is configured to generate almost no damping force when contracted. Therefore, when returning the steered steering, almost no damping force is generated. In this way, the steering damper device generates a damping force in any case when the steering wheel 7 is turned to the right or left from the steering angle 0 °, and the damping force is small when the steering wheel 7 is returned to the steering angle 0 °. Can be.

  Moreover, in the case of this steering damper device, the extension amount of the cylindrical damper 10 with respect to the steering angle of the handle 7 is small in the vicinity of the neutral position of the handle 7, and the steering angle of the handle 7 is increased in a region where the steering angle is larger. The damper stroke gradually increases. That is, the sliding amount of the damper rod 12 with respect to the steering wheel steering angle is small when the steering wheel steering angle is near 0 °, and is increased as the steering wheel steering angle goes away from 0 °. Therefore, when the steering wheel 7 is steered from the neutral position, as shown in FIG. 10, almost no damping moment is generated at the initial stage, and the damping force gradually increases in the middle. That is, the damping force that acts on the front fork 2 that is the steering side member from the cylindrical damper 10 is small when the steering angle of the steering wheel is 0 °, and increases as the steering angle of the steering wheel is separated from 0 °. Moreover, it continues smoothly during that time. Thus, this steering damper device can provide desirable characteristics desired for the steering damper device of a motorcycle.

  As described above, the damping coefficient of the cylindrical damper 10, that is, the magnitude of the damping force with respect to the sliding amount of the damper rod 12 is large when the cylindrical damper 10 is contracted, and decreases as it expands. Has been. In other words, the steering angle is large in the vicinity of 0 °, and the steering angle is decreased as the steering angle is away from 0 °. Therefore, in the region where the steering wheel steering angle is large, even if the sliding amount of the damper rod 12 with respect to the steering wheel steering angle increases, the damping force does not increase so much. As a result, as shown in FIG. 10, the increase in the damping moment becomes dull in the region where the steering wheel steering angle is large. Therefore, even when the steering wheel is largely steered while the motorcycle is traveling at a low speed, the steering operation can be performed lightly. it can.

  FIGS. 11 to 14 show a second embodiment of a steering damper device according to the present invention. FIG. 11 is a longitudinal side view showing a main part of a cylindrical damper used in the steering damper device, and FIG. 12 is different. 11 is a longitudinal side view similar to FIG. 11 showing the operating state, FIG. 13 is a cross-sectional view taken along line 13-13 in FIG. 11, and FIG. 14 is a cross-sectional view taken along line 14-14 in FIG.

  The second embodiment is different from the first embodiment only in the cylindrical damper used, and the overall configuration is the same as that of the first embodiment. By attaching the same reference numerals, overlapping description is omitted.

  As is apparent from FIGS. 11 to 14, the cylindrical damper 40 of the second embodiment omits the valve spring 30 in the cylindrical damper 10 of the first embodiment, and instead has a groove in the peripheral wall of the damper chamber 15. 41 is provided.

  That is, also in the cylindrical damper 40 of the second embodiment, the piston body 23 of the piston 20 attached to the tip of the damper rod 12 has a plurality of notches 21 and 21 on the outer periphery of the upper and lower ends. ..., 22, 22 ... are formed, and the piston body 23 has first through holes 24, 24 ... whose upper ends open to the upper end surface of the piston body 23 and whose lower ends open to the notch 22; There are provided second through holes 25, 25... Having a lower end opened in the lower end surface of the piston body 23 and an upper end opened in the cutout portion 21. The upper end of the first through hole 24 is controlled to open and close by a valve plate 26 made of an elastic plate, and the lower end of the second through hole 25 is controlled to open and close by a similar valve plate 27. The upper valve plate 26 is relatively high in rigidity, and a central portion thereof is fixed through a washer 29 by a nut 28 fastened to the upper end portion of the damper rod 12, and is usually in close contact with the upper end surface of the piston body 23. It is to be held in the state. Further, the lower valve plate 27 is pressed and biased upward by a valve spring 33 that is contracted between the lower spring plate 32 and a spring receiver 32 supported by the damper rod 12. 23 is held in close contact with the lower end surface of 23. The valve spring 33 has a small spring force.

  A groove 41 extending in the vertical direction longer than the vertical dimension of the piston main body 23 is formed in the peripheral wall of the damper chamber 15 at a position where the piston main body 23 faces when the cylindrical damper 40 extends.

  In the steering damper device provided with the cylindrical damper 40 having such a configuration, when the handle 7 is in the neutral position and the cylindrical damper 40 is most contracted, as shown in FIG. The surface is in contact with the inner peripheral surface of the damper chamber 15 on the entire periphery. When the handle 7 is turned to the left or right from this state, the cylindrical damper 40 is extended, and the piston 20 attached to the tip of the damper rod 12 slides toward the lower side of the damper chamber 15. Therefore, the pressure in the lower chamber 15b of the damper chamber 15 is increased, and the pressure passes from the notch portion 22 on the outer periphery of the lower end portion of the piston body 23 to the outer peripheral portion of the valve plate 26 through the first through hole 24. Operates from the bottom side. As a result, the outer peripheral portion of the valve plate 26 is pushed up as shown by a two-dot chain line in FIG. 11 and is separated from the upper end surface of the piston body 23. Therefore, the oil in the lower chamber 15b flows to the upper chamber 15a as shown by the solid line arrow in FIG. A damping force is generated by the resistance of the oil passing through the gap between the valve plate 26 and the piston main body 23. In that case, since the valve plate 26 has high rigidity and is relatively difficult to deform, the gap formed between the valve plate 26 and the piston main body 23 at that time is small. Therefore, the damping coefficient of the cylindrical damper 40 at that time is large.

  When the cylindrical damper 40 extends to some extent and reaches the position where the piston body 23 faces the groove 41 as shown in FIG. 12, the oil in the lower chamber 15b of the damper chamber 15 is indicated by a solid line arrow in FIG. As shown, since it flows to the upper chamber 15a even through the groove 41, the resistance to the oil flow is reduced. That is, the damping coefficient of the cylindrical damper 40 is reduced.

  Thus, also in the case of this cylindrical damper 40, the damping coefficient, that is, the magnitude of the damping force with respect to the sliding amount of the damper rod 12 is large when the cylindrical damper 40 is contracted, and as it expands. Get smaller.

  On the other hand, when the cylindrical damper 40 contracts, the pressure in the upper chamber 15a of the damper chamber 15 increases, so that the periphery of the lower valve plate 27 as shown by the two-dot chain line in the lower right portion of FIGS. The portion deforms downward against the urging force of the valve spring 33. As a result, the gap between the valve plate 27 and the lower end surface of the piston body 23 is opened, and the oil in the upper chamber 15a passes through the second through hole 25 as shown by the broken line arrows in FIGS. It flows to the lower chamber 15b. In this case, since the valve plate 27 is easily deformed, almost no damping force is generated at this time.

  Therefore, the same effects as those of the first embodiment can be obtained by the steering damper device of the second embodiment.

  FIGS. 15 to 18 show a third embodiment of a steering damper device according to the present invention. FIG. 15 is a longitudinal side view showing a main part of a cylindrical damper used in the steering damper device, and FIG. 16 is different. 15 is a longitudinal side view similar to FIG. 15 showing the operating state, FIG. 17 is a sectional view taken along the line 17-17 in FIG. 15, and FIG. 18 is a sectional view taken along the line 18-18 in FIG.

  In the third embodiment, the cylindrical damper used is different from that of the first embodiment, and the overall configuration is the same as that of the first embodiment. By attaching the same reference numerals, overlapping description is omitted.

  As is apparent from FIGS. 15 to 18, the cylindrical damper 50 of the third embodiment omits the valve spring 30 in the cylindrical damper 10 of the first embodiment, and instead, at the tip of the damper rod 12. A flow path 51 having a variable throttle mechanism is provided.

  Also in the case of the cylindrical damper 50 of the third embodiment, the piston 20 attached to the tip of the damper rod 12 has the same configuration as that of the above-described second embodiment. And the flow path 51 which consists of the center hole 51a and the radial direction hole 51b is provided in the front-end | tip part of the damper rod 12. As shown in FIG. The center hole 51 a is open to the upper chamber 15 a of the damper chamber 15 at the upper end surface of the damper rod 12 and extends downward from the mounting portion of the piston 20. The radial hole 51b communicates the center hole 51a with the lower chamber 15b of the damper chamber 15. On the other hand, the upper end surface of the damper chamber 15 is provided with a taper-shaped protrusion 52 that protrudes long downward from its central portion and whose diameter decreases downward. The protrusion 52 is inserted into the center hole 51a at the tip of the damper rod 12.

  In the steering damper device having the cylindrical damper 50 having such a configuration, when the handle 7 is in the neutral position and the cylindrical damper 50 is most contracted, the center of the damper rod 12 is shown in FIG. Since the upper end of the hole 51a faces the large diameter portion of the protrusion 52, the gap formed between them is small. That is, the channel area of the channel 51 is small. From this state, when the handle 7 is turned to the left or right, the cylindrical damper 50 extends, and the piston 20 attached to the tip of the damper rod 12 slides toward the lower side of the damper chamber 15. The pressure in the lower chamber 15b of the damper chamber 15 increases. Therefore, the oil in the lower chamber 15b passes through the flow path 51 formed in the damper rod 12 as shown by the solid line arrow in FIG. 15, and the first through hole 24 as in the second embodiment. From the valve plate 26 and the piston body 23 to the upper chamber 15a. A damping force is generated by the resistance acting on the oil at that time. In that case, the flow path area formed in the flow path 51 is small as described above, and the gap formed between the valve plate 26 and the piston main body 23 is also small. Therefore, the damping coefficient of the cylindrical damper 50 at that time is large.

  When the cylindrical damper 50 extends according to the steering angle of the handle 7, the upper end of the center hole 51 a of the damper rod 12 faces the small diameter portion of the protrusion 52 as shown in FIG. Since the flow passage area of the oil increases, the resistance to the oil flow decreases. That is, the damping coefficient of the cylindrical damper 50 is reduced.

  Thus, also in the case of this cylindrical damper 50, the damping coefficient, that is, the magnitude of the damping force with respect to the sliding amount of the damper rod 12 is large when the cylindrical damper 50 is contracted, and as it expands. Get smaller.

  On the other hand, when the cylindrical damper 50 contracts, the pressure in the upper chamber 15a of the damper chamber 15 increases, so that the oil in the upper chamber 15a is broken in FIGS. As indicated by the arrow, the air flows through the second through hole 25 to the lower chamber 15b. In this case, since the valve plate 27 is easily deformed, almost no damping force is generated at this time.

  Therefore, the same effect as that of the first embodiment can be obtained by the steering damper device of the third embodiment.

  19 and 20 show a fourth embodiment of a steering damper device according to the present invention. FIG. 19 is a side view of a fork bridge portion of a front fork of a motorcycle equipped with the steering damper device. FIG. It is the front view seen from the arrow 20 direction of 19.

  In addition, in this 4th Example, the description which overlaps abbreviate | omitting by attaching | subjecting the same code | symbol to the part corresponding to 1st Example.

  As shown in FIGS. 19 and 20, in the case of the fourth embodiment, a link lever 58 having a substantially triangular shape is formed at the front end portion of the stay 8a protruding forward from the central portion in the vertical direction of the head pipe 6h. , And is supported rotatably via a horizontal shaft 59. A cylindrical damper 60 is disposed between the link lever 58 and the upper end of the head pipe 6h. The cylindrical damper 60 includes a damper case 61 and a damper rod 62 that slides in the damper case 61. The damper case 61 is rotated to the front surface of the upper end of the head pipe 6h via a horizontal shaft 63. The damper rod 62 is rotatably connected to the front end portion of the link lever 58 via the horizontal shaft 64. On the other hand, a link rod 65 is rotatably connected to the front surface of the lower end of the link lever 58 via a spherical joint 66, and the other end of the link rod 65 is a bottom bridge 4 b that forms the lower part of the fork bridge 4. Is connected to the front surface of the central portion in the left-right direction via a spherical joint 67 so as to be rotatable.

  In this manner, the cylindrical damper 60 is connected to the vehicle body frame 6 that does not rotate even when the handle is operated, and is rotated about the steering stem 5 by the handle operation via the link lever 58 and the link rod 65. The steering side member is connected to the fork bridge 4. When the handle 7 is in the neutral position, that is, when the steering angle of the steering wheel is 0 °, the link rod 65 has a straight line L connecting the centers of the spherical joints 66 and 67 that are connecting portions at both ends of the link rod 65. The stem 5 is disposed so as to be positioned on a vehicle body center plane including the center axis S of the stem 5 and extending in the vehicle body longitudinal direction.

  Further, the cylindrical damper 60 is similar to the cylindrical dampers 10, 40, 50 of the first to third embodiments described above, and generates a damping force when it is extended, and almost has a damping force when it contracts. It does not occur, and the attenuation coefficient is large when the steering angle of the steering wheel is 0 °, and is small as the steering angle of the steering wheel is away from 0 °.

  Other configurations are the same as those of the first embodiment.

  In the steering damper device configured as described above, for example, when the handle 7 is cut to the left, the front fork 2 is rotated leftward about the central axis S of the steering stem 5 and the bottom bridge 4b is similarly rotated. Therefore, the spherical joint 67 coupled to the front center of the bottom bridge 4b moves to a position indicated by a two-dot chain line in FIG. As a result, the spherical joint 66 coupled to the link lever 58 is pulled down by the link rod 65 coupled to the spherical joint 67, and the link lever 58 is centered on the horizontal axis 59 in FIG. Rotate as shown by the arrow. Accordingly, the cylindrical damper 60 extends, and a damping force is applied from the cylindrical damper 60 to the bottom bridge 4b of the steering side member. Also, when the handle 7 is turned to the right, the spherical joint 66 on the link lever 58 side is pulled down, so that the cylindrical damper 60 is similarly extended and a damping force is generated.

  When the handle 7 is largely cut, the extension amount of the cylindrical damper 60 is also increased. At this time, the damping coefficient is reduced, so that the generated damping force is not so large. Therefore, it is possible to prevent the handle operation from being felt heavy.

  When the handle 7 cut to the right or left is returned to the neutral position, the cylindrical damper 60 contracts in any case, so that almost no damping force is generated.

  In this way, the same effects as those of the first embodiment can be obtained by the steering damper device of the fourth embodiment. In the case of this steering damper device, the movement of the steering side member is transmitted to the cylindrical damper 60 via the link rod 65 and the link lever 58, so that the cylindrical damper 60 is separated from the steering side member. In addition, it can be arranged in any direction. Therefore, the degree of freedom of arrangement of the cylindrical damper 60 can be further increased.

  The preferred embodiments of the present invention have been described above, but the present invention is not limited to these embodiments, and various embodiments are possible within the scope of the present invention.

  For example, the cylindrical damper 10 uses a double-tube type in which a reservoir chamber 17 is provided on one side of the damper chamber 15 as in the above embodiments, and a reservoir chamber is provided on the outer periphery of the damper chamber. You can also. Further, instead of the compressed gas 19 for biasing the piston 18 provided on the reservoir chamber 17 side, a compression spring may be used, or both of them may be used. Furthermore, the present invention can be applied to other vehicles such as a four-wheel buggy in addition to the motorcycle as in the above-described embodiment.

  It is also possible to use a cylindrical damper that is the longest in the vicinity of the steering angle of 0 °, or to arrange the cylindrical damper in the longitudinal direction of the vehicle body. In such a case, the cylindrical damper does not necessarily need to be disposed on the center plane in the front-rear direction of the vehicle body when the handle 7 is in the neutral position, and is disposed slightly shifted from the center plane in the front-rear direction of the vehicle body. You can also. Furthermore, the cylindrical damper 10 can be provided between the top bridge 4 a of the fork bridge 4 and the vehicle body frame 6.

The side view of the principal part which shows the motorcycle equipped with the steering damper apparatus of 1st Example of this invention. FIG. 1 is a front view of the front fork viewed from the direction of arrow 2 in FIG. Sectional drawing of the cylindrical damper part along line 3-3 in FIG. Enlarged cross-sectional view along line 4-4 in FIG. Sectional view along line 5-5 in FIG. Sectional drawing which follows the 6-6 line of FIG. Exploded perspective view of piston of cylindrical damper Front view similar to FIG. 2 showing a state when the steering wheel is steered from the neutral position to the left side Sectional view along line 9-9 in FIG. Characteristic curve diagram of the steering damper device Vertical side view showing the main part of the cylindrical damper used in the steering damper device of the second embodiment of the present invention Vertical side view similar to FIG. 11 showing different operating states Sectional drawing which follows the 13-13 line of FIG. Sectional drawing which follows the 14-14 line of FIG. Vertical side view showing the main part of a cylindrical damper used in the steering damper device of the third embodiment of the present invention Vertical side view similar to FIG. 15 showing different operating states Sectional drawing which follows the 17-17 line of FIG. Sectional drawing which follows the 18-18 line of FIG. Side view of a fork bridge portion of a front fork of a motorcycle including a steering damper device according to a fourth embodiment of the present invention. Front view seen from the direction of arrow 20 in FIG.

Explanation of symbols

1 ・ ・ Front wheel 2 ・ ・ Front fork 4 ・ ・ Fork bridge (steering side member)
4a ··· Top bridge 4b ··· Bottom bridge 5 · · Steering stem 6 · · Body frame (vehicle body side member) 6h · · Head pipe 10 · · Cylindrical damper 11 · · Damper case 12 · · Damper rod 15 · · Damper Room 15a ... Upper room (first room) 15b ... Lower room (second room)
20. Piston 24. First passage (first through hole)
25 .. Second passage (second through hole)
26 .. First valve plate 27. Second valve plate 30 First valve spring 33 Second valve spring 40 Tubular damper 50 Tubular damper 51 Third passage (flow path)
52 ·· Projection 60 · · Cylindrical damper 61 · · Damper case 62 · · Damper rod

Claims (7)

Steering side in which a damper rod (12, 62) rotates a cylindrical damper (10, 40, 50, 60) in which a damper case (11, 61) slides around a steering stem (5) by a handle operation. In the steering damper device provided between the member (4b) and the vehicle body side member (6h) that does not rotate even when the steering wheel is operated,
The sliding amount of the damper rod (12, 62) with respect to the steering wheel steering angle is small when the steering wheel steering angle is close to 0 °, and increases as the steering wheel steering angle goes away from 0 °.
When the steering coefficient of the cylindrical damper (10, 40, 50, 60) corresponding to the magnitude of the damping force with respect to the sliding amount of the damper rod (12, 62) is cut from a steering angle of 0 °, The steering angle is large in the vicinity of 0 °, and becomes smaller as the steering angle of the steering wheel is away from 0 °. When the steering wheel is returned to the steering angle of 0 °, it is smaller than when the steering wheel is turned from the steering angle of 0 °. A steering damper device, characterized in that: Steering side in which a damper rod (12, 62) rotates a cylindrical damper (10, 40, 50, 60) in which a damper case (11, 61) slides around a steering stem (5) by a handle operation. In the steering damper device provided between the member (4b) and the vehicle body side member (6h) that does not rotate even when the steering wheel is operated,
The damping force that acts on the steering side member (4b) from the cylindrical damper (10, 40, 50, 60) is small when the steering angle is near 0 °, and increases as the steering angle is away from 0 °. As well as
When the steering coefficient of the cylindrical damper (10, 40, 50, 60) corresponding to the magnitude of the damping force with respect to the sliding amount of the damper rod (12, 62) is cut from a steering angle of 0 °, The steering angle is large in the vicinity of 0 °, and becomes smaller as the steering angle of the steering wheel is away from 0 °. When the steering wheel is returned to the steering angle of 0 °, it is smaller than when the steering wheel is turned from the steering angle of 0 °. A steering damper device, characterized in that: Steering side in which a damper rod (12, 62) rotates a cylindrical damper (10, 40, 50, 60) in which a damper case (11, 61) slides around a steering stem (5) by a handle operation. In the steering damper device provided between the member (4b) and the vehicle body side member (6h) that does not rotate even when the steering wheel is operated,
The sliding amount of the damper rod (12, 62) with respect to the steering wheel steering angle is small when the steering wheel steering angle is near 0 °, and increases as the steering wheel steering angle goes away from 0 °, and the cylindrical dampers (10, 40, 50, 60), the damping force acting on the steering side member (4b) is small when the steering angle of the steering wheel is 0 °, and is increased as the steering angle of the steering wheel is separated from 0 °.
When the steering coefficient of the cylindrical damper (10, 40, 50, 60) corresponding to the magnitude of the damping force with respect to the sliding amount of the damper rod (12, 62) is cut from a steering angle of 0 °, The steering angle is large in the vicinity of 0 °, and becomes smaller as the steering angle of the steering wheel is away from 0 °. When the steering wheel is returned to the steering angle of 0 °, it is smaller than when the steering wheel is turned from the steering angle of 0 °. A steering damper device, characterized in that: The steering damper device according to any one of claims 1 to 3,
The cylinder damper rod (12, 62) includes a piston (20) for partitioning a damper chamber (15) for accommodating oil in the damper case (11, 61) into first and second chambers (15a, 15b). And a passage (24) through which oil flows between the first and second chambers (15a, 15b) between the first and second chambers (15a, 15b) as the piston (20) slides. 25, 51, 41), and by changing the flow resistance of the passage (24, 25, 51, 41) according to the sliding position of the piston (20), the damping coefficient is When the steering angle is turned from 0 °, the steering angle is large in the vicinity of 0 °, and becomes smaller as the steering angle is away from 0 °. When the steering wheel is returned to the steering angle of 0 °, the steering angle is 0. Cut from ° A steering damper device characterized in that the steering damper device is made smaller than when it is operated. The steering damper device according to claim 4, wherein
The piston (20) is provided with a first passage (24) through which oil flows between the first and second chambers (15a, 15b) as the piston (20) slides, and a handle is provided. A first valve plate (26) is attached that opens the first passage (24) when the steering angle is turned from 0 °, and closes the first passage (24) when the steering wheel is returned to the steering angle 0 °, The first valve plate (26) is urged by the first valve spring (30) in the closing direction of the first passage (24), and the urging force of the first valve spring (30) is applied to the steering angle of the steering wheel. Is larger in the vicinity of 0 °, and the steering angle becomes smaller as the steering angle is away from 0 °.
The piston (20) is provided with a second passage (25) through which oil flows between the first and second chambers (15a, 15b) as the piston (20) slides. A second valve plate (26) that closes the second passage (25) when the steering angle is turned from 0 ° and opens the second passage (25) when the steering wheel is returned to the steering angle 0 ° is attached, The second valve plate (27) is biased by the second valve spring (33) in the closing direction of the second passage (25), and the biasing force of the second valve spring (33) is the first valve spring (33). A steering damper device characterized by being made smaller than the urging force of the valve spring (30) against the first valve plate (26). The steering damper device according to claim 4, wherein
The piston (20) is provided with a first passage (24) through which oil flows between the first and second chambers (15a, 15b) as the piston (20) slides, and a handle is provided. When the steering angle is cut from 0 °, the first passage (24) is opened, and when the steering wheel is returned to the steering angle of 0 °, the first passage (24) is closed and biased in the closing direction. 1 valve plate (26) is attached,
The piston (20) is provided with a second passage (25) through which oil flows between the first and second chambers (15a, 15b) as the piston (20) slides. When the steering angle is turned from 0 °, the second passage (25) is closed, and when the steering wheel is returned to the steering angle of 0 °, the second passage (25) is opened and the second passage is biased in the closing direction. A valve plate (26) is attached, and the biasing force in the closing direction of the second valve plate (27) is smaller than the biasing force in the closing direction of the first valve spring (30),
The damper case (11, 61) is provided with a groove (41) that communicates between the first and second chambers (15a, 15b) only when the steering angle of the steering wheel is greater than a predetermined value. A steering damper device. The steering damper device according to claim 4, wherein
The piston (20) is provided with a first passage (24) through which oil flows between the first and second chambers (15a, 15b) as the piston (20) slides, and a handle is provided. When the steering angle is cut from 0 °, the first passage (24) is opened, and when the steering wheel is returned to the steering angle of 0 °, the first passage (24) is closed and biased in the closing direction. 1 valve plate (26) is attached,
The piston (20) is provided with a second passage (25) for allowing oil to flow between the first and second chambers (15a, 15b) as the piston (20) slides. When the steering angle is turned from 0 °, the second passage (25) is closed, and when the steering wheel is returned to the steering angle 0 °, the second passage (25) is opened and the second passage (25) is urged in the closing direction. Two valve plates (26) are attached, and the biasing force in the closing direction of the second valve plate (27) is smaller than the biasing force in the closing direction of the first valve spring (30),
Further, the piston (20) is provided with a third passage (51) through which oil flows between the first and second chambers (15a, 15b) as the piston (20) slides. The case (11, 61) is provided with a tapered protrusion (52) to be inserted into the third passage (51), and the protrusion (52) increases the first steering wheel as the steering angle of the steering wheel moves away from 0 °. A steering damper device having a tapered shape so as to increase a flow path area of the passage (24).

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